1. Institute of Epidemiology and Medical Biometry, Ulm University, Ulm
2. Swiss Tropical and Public Health Institute
3. University of Basel, Basel, Switzerland
4. Department of Pediatrics and Adolescents, Division of Cardiology and Pulmonology, Innsbruck Medical University, Innsbruck, Austria
5. 1st Department of Paediatrics, Allergology and Cardiology, Wroclaw Medical University, Wroclaw, Poland
6. LMU Munich, University Children's Hospital, Munich, Germany
7. Imperial College London, National Heart and Lung Institute, London, UK
8. Division of Environmental Epidemiology, Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, the Netherlands